Related Resource

Forensic Analysis: Weighing Bullet Lead Evidence (February 2004)

Since the 1960s, FBI testimony in thousands of criminal cases has relied on evidence from Compositional Analysis of Bullet Lead (CABL), a forensic technique that compares the elemental composition of bullets found at a crime scene to the elemental composition of bullets found in a suspect's possession. The report assesses the scientific validity of CABL, finding that the FBI should use a different statistical analysis for the technique, and that, given variations in bullets manufacturing processes, expert witnesses should make clear the very limited conclusions that CABL results can support.